I. Field of the Invention
The present invention is directed to a device for carrying cargo, and more particularly, to such a device attachable to a motor vehicle.
II. Description of the Prior Art
Cargo carriers which are attachable to motor vehicles have long been known. Some known cargo carriers are trailers, having one or more wheels which bear a substantial portion of the weight of the load carried by the carrier. Cargo trailers are conventionally attached to a motor vehicle through a trailer hitch affixed to the lower rear portion of the vehicle, generally at or below the vehicle bumper. Other cargo carriers comprise a rack or platform attached to one or more portions of the vehicle, such as a trailer hitch, the vehicle body or the vehicle bumper. Several carriers are known in which an end of a platform portion of the carrier is affixed to a portion of the vehicle above the trailer hitch, and a support member extends from the opposing end of the platform downward to the trailer hitch. The support member engages the trailer hitch to provide additional support for the platform.
Although the known cargo carriers generally function adequately for their intended purposes, their use on motor vehicles is often subject to several drawbacks. The known cargo carriers are of relatively complex structure, and are thereby rendered relatively expensive to produce. The support structures associated with these carriers require a substantial amount of time for assembly and for attachment to a vehicle. Moreover, a cargo carrier having a platform whose end must be affixed to the vehicle bumper or body may well damage that vehicle body or bumper when attached thereto.
The cargo carrying rack disclosed by Tartaglia, in U.S. Pat. No. 4,394,947, overcomes some of these problems, by providing a cargo carrier which is connected solely to the tongue of a standard trailer hitch. That carrier comprises a rack and a vertical member attached to one end of the rack, the vertical member having a threaded rod which is inserted through a corresponding hole in the trailer hitch. A pair of support brackets extend from the other end of the platform and are also affixed to the trailer hitch. These support brackets are attached to a pair of plates which engage and trap the trailer hitch tongue therebetween.
While the cargo rack of Tartaglia functions adequately for its intended purpose, its use incurs several drawbacks. The structure is relatively complex and takes some time to attach to the vehicle. Moreover, although not specifically disclosed in the patent, the cargo platform will necessarily be carried at some substantial height above the trailer hitch tongue. Presumably, this vertical displacement must be sufficient to permit the support brackets to provide some vertical support for the weight of the rack and the cargo carried thereon. In the embodiment shown in FIG. 2 of Tartaglia, the platform of the carrier is disclosed to be about level with the top of the trunk portion of the automobile on which the rack is carried. Cargo placed on the platform will necessarily sit outside a substantial portion of the slipstream created by the aerodynamic surfaces of the automobile body. Thus, the cargo rack will increase the wind resistance of the vehicle and decrease, albeit by a small amount, the fuel efficiency of the vehicle.
Of course, conventional trailers pulled by a trailer hitch suffer drawbacks as well. A complex support or spring system is often necessary to avoid transferring road shocks through the wheels to the cargo carried by the trailer. Because wheels are employed, the trailer is subject to the vagarities associated with a wheeled vehicle such as flat tires and the like. For these reasons, there is some not inconsiderable expense incurred in providing a cargo carrier with ground-engaging wheels.